KINGSTON — The seriousness and extent of a second sinkhole on Washington Avenue won't be known for at least another month, Kingston officials said.

The new sinkhole, which is between 3 and 4 feet deep and about 10 feet in diameter, appeared on Friday, and has prompted a new series of well drillings, Kingston engineering technician Alan Adin said.

The original sinkhole, which developed in April 2012, has caused a block of Washington Avenue to be closed since then. Adin said the probable source of that sinkhole is a combination of century-old storm tunnels and sewer lines, as well as shifting in the limestone bedrock. The cost to repair that first hole is estimated at $1.8 million.